This invention relates to fluid pressurizing devices employing screw plungers, and more particularly relates to improved devices for actuating the screw plunger and monitoring the resulting fluid pressurization.
Fluid pressurization devices adapted for selectively applying and relieving a measured pressure on a closed volume of fluid have been developed for use in inflation and deflation for angioplasty balloon procedures interiorly of blood vessels. As described for example in U.S. Pat. No. 4,838,864, a syringe device inflates and deflates the catheterized balloon using a manually operated screw plunger to achieve or maintain specific pressure within the balloon which is monitored with an integral pressure gauge. The present invention provides an improved mechanism for attaining engagement and disengagement of the screw plunger as well as improved mechanism for monitoring the controlled fluid pressure.